Modern combustion engines may include one or more cylinders as part of the engine. The cylinder head and an associated piston may define a combustion chamber therebetween. Fuel for combustion is directly injected into the combustion chamber by, for example, a fuel injector which is associated with the cylinder, the fuel injector having at least one orifice disposed such that it can directly inject fuel into the combustion chamber.
Different mixtures and/or equivalence ratios of the fuel/air mixture may produce different results during combustion. A manner in which the injected fuel mixes and/or interacts with air and other environmental elements of the combustion chamber may impact the combustion process and associated emissions. Further, if the fuel and air mixing is inadequate, then suboptimal or abnormally large amounts of soot may form within the combustion chamber.
U.S. Pat. No. 7,942,126 discloses a method for operating an internal combustion engine having a piston with a piston recess which includes a transitional region with an annular stepped space. The patent discloses directing fuel jets, injected by the fuel injector, towards the annular stepped space. The fuel jet is deflected by the annular stepped recess such that a first portion of the fuel jet is deflected towards the piston recess, a second portion of the fuel jet is deflected into a combustion space and towards a wall of a cylinder, and a third portion of the fuel jet is deflected in a circumferential direction.